Sewing-machine pull-off.



P. DIEHL & M. HBMLEB. SEWING MACHINE PULL-OFF. APPLIOATION FILED NOV. 18, 1912.

1 ,105,968, Patented Aug. 4, 1914.

IN V E N TQRS k1," W W/M ATTORNEY rmm nmm. m

mm HEKLEIB, 0F ELIZABETH NEW JERSEY, ASSIGNOBS T0 In SINGER MANUFACTURING COMPANY, A CORPORATION OF NEW JERSEY.

SEWING-MACH INE PULL-OFF.

Specification of Letters Patent.

Patented Aug. 4, 1914-.

Application m November 19, 1912. semi in. 731,922.

To all whom it may concern: I

Be it known that we, PHILIP Dunn. and MARTIN HEMLE'B, citizens of the United States, residing at Elizabeth, in the county of Umon and State of New Jersey, have invented certain new and useful Improvements in Sewing-Machine Pull-Offs, of which the following is a specification, reference being had therein to the accompanying drawings.

While ap licable to different classes of sewing mac ines employing a rotary looptaker carryin a lower thread, the present improvement is designed chiefly for embodiment in that class of lock-stitch loop-takers having a plurality of rotations imparted thereto for each reciprocation of the needle. It has been customary heretofore to provide such a loop-taker with a pull-01f flange acting to draw" thread from the bobbin-case for each stitch; but with a plural-rotation looptaker so fitted, the lower thread is repeatedly engaged by the ull-ofl element in eac stitch-forming cyc e, thereby disturbing the previously set stitch and impairing the effectiveness and appearance of the seam.

The present invention therefore has for its primary object to provide the described class of rotary loop-taker machines with simple and effective means for properly drawing off the lower thread for each stitch without affecting the previously formed and set stitch.

In the preferred embodiment of the invention, the non-rotary thread-case is journaled in the loop-taker and has athreadguiding arm or projection over which the lower thread is led to the work, and the feed-dog is provided with a pull-off rib or flange movable vertically between the thread-guiding arm of the thread-case and the needle-path which determines the position of the needle-hole of the throat-plate through which the lower thread passes to the work in the stitching operation. By this means, the loop-taker is entirely relieved of its lower thread drawing function, thus avoiding the dislodgment of the previous stitch in a succeeding stitch-forming cycle, and the feed-dog, which makes only a single excursion for each stitch, is caused to draw oil the lower thread for a succeeding stitch just at the time when the needle is descending and when its eye is below the work and the portion of the needle-thread leading therefrom to the previous stitch is nipped overlying loop-deflector spur 22,

in the goods and held taut so as to resist the strain upon the lower thread imposed by In the accompanying drawings, Figure 1 is .an elevation, with the frame in section, of a Singer rotary hook machine similar to that represented in the application Serial No. 728,779, filed October 31, 1912, and

Fig. 2 an end new of the parts below the bed-plate which latter is represented in transverse section. Fig. 3 is 3, pers 'ective view representing the member of the t readcase formed with the thread-guidingarm, a portion of the throat-plate and the'fe'eddog with its pull-ofl element acting upon the lower thread. Figs. 4 and 5 are sectional elevations of the parts represented in 3, with both membersof the thread-case, and showing the feed-dog in its extreme upper and lower positions. Fig. 6 is a perspective view of the thread-case member provided with the thread-guiding arm, and Fig. 7 a pers ective view, taken from the lower side, 0 the feed-dog provided with the pull-ofi rib or flange.

As represented in the drawings, the frame of the machine is constructed with the bedplate 1, hollow stafiard 2 and tubular arm 3 in which is jou aled the main-shaft 4 carrying at its rearward end the balance wheel 5 and at its forward end the crankplate 6 provided with the crank-pin 7 connected by means of the pitman 8 with the collar 9 fixed upon the needle-bar 10, which is provided with the needle 11. Upon the rearward portion of the main-shaft is fixed the bevel-gear 12 meshing with a bevel pinion 13 upon the upper end of a vertical shaft 14 having upon its lower end the bevel pinion 15 meshing with a similar pinion 16 upon the loop-taker shaft 17 suitably journaled beneath the bed-platel The gear 12 is twice the diameter of the pinion 13, and therefore imparts to the vertical shaft 14, and through it to the loop-taker shaft 17, two rotations for each rotation of the main-shaft, and hence for each reciprocation of the needle.

Fixed upon the forward extremity of the shaft 17 is the hub 18 of the loop-taker 19 in the form of a cup-shaped hook provided with a central thread-cavity 20 and with a loop-seizing beak 21 and with spaced and as shown and described more fully in the pending application Serial No. 638,059, filed July 12, 1911. The thread-cavity is provided with the usual annular groove in which is journailed the peripheral bearing rib 23 of the body portion or carrier 24 of the threadcase, which is formed with the central pin 25 and with the forwardly projecting tongue or extension 26 containing the needle clearance aperture 27 and provided with the outwardly extending thread-guiding flange or lip 28 which is shown in the drawings formed with the thread-leading groove or notch 29. The thread-case cap or cover 30 is provided, as represented in the said application Ser. No. 638,059, with the tension spring 31 secured in position by means of the fastening screw 32, and is provided with a tubular post fitted upon the pin 25 and adapted to receive the lower thread bobbin. The cap member 30 is provided with a latch device 33 having a latch element adapted to engage the notched outer end of the pin 25 for locking such member inplace.

The notch 29 of the guide-member 28 is entered by a lateral lug 34 of a holding arm 35 secured upon the bot-tom of the bed-plate 1, so as to restrain the carrier member 24 of the thread-case from turning with the hook, while the cap-member has the usual interlocking connection with the latter whereby it is maintained stationary in the operation of the machine,

The main-shaft 4 has the usual feed-actuating eccentric 36 and feed-lift eccentric 37, upon the former of which is fitted a collar 38 embraced by the fork 39 at the upper end of the link-bar 40. The link-bar has the usual pivotal connection at 40 with a swinging supporting link whose fulcrum is laterally adjustable to vary the resultant vertical movement of the link-bar, as is common to many sewing machines of the Singer type. At its lower end the link-bar is pivotally connected by means of the stud-pin 41 with the lateral arm 42 of the feed rock-shaft 43 journaled beneath the bed-plate and provided with upright arms 4-1 affording a yoke in which is journaled upon the pins 45 the cross member 4-6 at one end of the feed-bar 47. The opposite end the feed-bar is formed with a fork 48 adapted to embrace the roller-stud 49 carriedby the lateral arm 50 of the feed rock-shaft 51 having at its rearward end the lateral arm 52 pivotally connected to the lower end of the pitmanrod 53 whose upper end is provided with the strap 54 embracing the feed-lift eccentric 37.

Secured upon the seat 47 of the feed-bar 47 is theshank 56. of the feed-dog provided with the serrated feeding surfaces 57 adapted to-inove upwardly through the usual apertures 58 of the throat-plate 59, and

formedin its lower side with the recess 60 to after clearance for" the loop-taker beak. Depending from the upper wall of the recess 60 intermediate the extreme feeding surfaces 57 of the feed-dog is the pull-01f rib or flange 61 which, as represented in the drawings, is disposed in a plane intermediate the guidearm 28 of the thread-case member 24 and the plane of movement of the loop-taker beak 21 and of the needle.

In threading the machine, the lower thread 8 passes from beneath the tension spring 31 through the delivery eye 30' of the capmember 30 of the thread-case, and thence upwardly through the usual needle-hole 59' of the throat-plate, as represented in Figs. 2 and 4. The initial stitch or stitches having been formed and set by the action of the takeup arm 62 connected with the needleactuating crank 7, upon the descent of the needle to present a thread-loop for seizure by the loop-taker beak, the feed-dog eflects its descent, carrying with it the pull-ofl' flange 61 which produces a crook in the lower thread 8, just at the time when the upper thread 1:. leading to the previous stitch is taut and securely nipped between the ungrooved side of the needle above the eye and the puncture in the fabric m. The bending of the lower thread while its outer end is securely anchored in the fabric by engagement with the taut needle-thread causes the drawing of the succeeding supply through the lower-thread tension so as to properly locate within the body of the material the interlock of the threads in the setting of the stitch formed by the cycle as thus begun.

It is evident that the pull-ofl member, While preferably formed upon a part of the feed-dog, may be otherwise sustained and actuated, within the scope of the present invention, and that the particular means employed for directing the lower thread from the thread-case and restraining the latter from rotation are not essential.

Having thus set forth the nature of the invention, what we claim herein is 1. In a sewing machine, the combination with a reciprocating needle, and a rotary loop-taker formed with a thread-cavity and with a loop-seizing beak having a path of movement around an axis transverse to said needle, of a non-rotary thread-case disposed within the thread-cavity of said'Ioop-taker and provided with a thread-guiding member at one side of the needle-path, and a reciprocatory pull-off member having operative rectilinear movements in a path substantially parallel with the needle and interme- (biiate the needle-path and said guide-mem- 2. In a sewing machine, the combination with a reciprocating needle, and a rotary loop-taker formed with a thread-cavity and with a loop-seizing beak having a path of movement around an axis transverse to said needle, of a non-rotary thread-case disposed within the thread-cavity of said loop-taker and provided with a thread-guiding member at one side of the path of movement of the loop-taker beak, and a reciprocatory pulloff member having operative movements in coaction with said thread guiding member in a plane substantially parallel with the path of movement of the loop-taker beak.

In a sewing machine, the combination with feeding mechanism comprising a feedbar with means for imparting thereto lateral and rising-and-falling movements, a reciprocating needle, and a rotary looptaker formed with a thread-cavity and with a loop-seizing beak having a pat of movement around an axis transverse to said needle, of a non-rotary thread-case disposed within the thread-cavity of said loop-taker and provided with a thread-guiding member at one side of the needle-path, and a pulloff member carried by the feed-bar and movable between said guide-member and the needle-path.

4. In a sewing machine, the combination with a reciprocating needle, a loop-taker formed with a thread-cavity and with a loop-seizing beak, and means for imparting to the loop-taker a plurality of rotations for each reciprocation of the needle, of a non-rotary thread-case carrying a lower thread disposed within the thread-cavity of said loop-taker and provided with a threadguiding arm over which the lower thread is led to the work, and a reciprocatory pulloff member adapted to engage the lower thread intermediate the thread-case arm and the needle.

5. In a sewing machine, the combination Copies of this gatent may be obtained for five cents each,

with feeding mechanism comprising a feedbar with means for imparting thereto lateral and rising-and-falling movements, a reciprocating needle, a loop-taker formed with a thread-cavity and with a loop-seizing beak, and means for imparting to the looptaker a plurality of rotations for each reciprocation of the needle, of a non-rotary thread-case carrying a lower thread disposed within the thread-cavity of said loop-taker and provided with a thread-guiding arm over which the lower thread is led to the work, and a pull-ofi' member carried by the feed-bar and movable between said guidemember and the needle-path.

6. In a sewing machine, the combination with a reciprocating needle and a rotary loop-taker formed with a thread-cavity and with a loop-seizing beak, of a non-rotary thread-case disposed within the thread-cavity of said loop-taker and formed with a thread-delivery eye, a thread guiding arm carried by said thread-case and formed with a thread-receiving groove in alinement with said delivery eye, a feed-bar, and a pull-off member carried by the feed-bar and movable between said guiding arm and the needle-path.

In testimony whereof, we have signed our names to this specification, in the presence of two subscribing witnesses.

PHILIP DIEHL. MARTIN HEMLEB.

\Vitnesses:

HENRY J. MILLER, HENRY A. KORNEMANN, Jr.

by addressing the Commissioner of Patents.

Washington, D. 0. 

